It is often desirable to test products and/or their component parts under conditions that are similar to those expected in the field. The test results may be used to help ensure that the products and/or their component parts will function properly in the field. For some applications, it is difficult to properly test the products and/or component parts, sometimes because of the extreme conditions for which they are intended to be used. For example, testing projectiles and/or components of such projectiles, such as circuit cards, during conditions of a ballistic event in a controlled and reproducible manner can be difficult. Similarly, testing acceleration sensors and/or cards during conditions of an automobile crash can be difficult. These are just a few examples.
The testing of components for use in a projectile would ideally include simulation of accelerative forces that are similar to those that are expected during actual service in the field. However, the associated long duration, high acceleration environment of ballistic applications, such as the firing of a gun, can typically not be adequately simulated in a laboratory environment. The ruggedness and reliability of many components generally cannot be qualitatively, quantitatively, or comparatively evaluated except under conditions which simulate their actual flight experience without the terminal destruction which would be experienced by actual flight. Not being able to simulate/test these high-g forces has presented some design challenges.
A typical method of simulating forces that are experienced by a projectile include using an “air gun” that accelerates a projectile by air pressure in a confined tube of suitable diameter. However, this and many other previous methods have a maximum force and/or duration that can be produced and simulated. For example, an air gun may be capable of producing levels up to 20,000 G's, but at these force levels, the duration of the event is typically less than a millisecond or so. For many ballistic applications, such as the firing of a gun, as well as other high-g applications, the events may extend over 10 milliseconds or more. Thus, it may be desirable to simulate relatively large forces over a relatively longer duration.